INA3221 breakout board

I have purchased a INA3221 breakout board from eBay to replace several INA219s. They differ from the switchdoc INA3221 breakout board and the INA219 in having no V+ and V-. Instead they have three channels with CH1/2/3 and GND. I have tried to connect these pins as V+ and V-, but there is no current. The CH channels seems connected as I can put V+ on one and V- on another channel and get voltage and current readings on both, but with reversed current direction.

The POW pins also connected to the CH pins. I can put V+ on POW and measure voltage and current on all three CH pins when connecting V- to those.

Have anyone has any luck using these sensors? Any good advice for hooking them up?

The module: http://www.ebay.com/itm/INA3221-3-Channel-Shunt-Current-Voltage-Monitor-Sensor-Replace-INA219-Module-/262946505125

That module doesn't bring out the 3 pairs of sense pins separately, it cannot be used as a high-side current sensor, only low-side. Ground is used as the return for all channels.

That is what I suspected. What a pity.... Guess I have to buy the Switchdoc module.

The description of the module is somewhat misleading…

The INA3221 is a three-channel, high-side current and bus voltage monitor with an I2C- and SMBUS-compatible interface. The INA3221 monitors both shunt voltage drops and bus supply voltages, in addition to having programmable conversion times and averaging modes for these signals. The INA3221 offers both critical and warning alerts to detect multiple programmable out-of-range conditions for each channel.

The INA3221 senses current on buses that can vary from 0 V to 26 V. The device is powered from a single 2.7-V to 5.5-V supply, and draws 350 µA (typ) of supply current. The INA3221 is specified over the operating temperature range of –40°C to +125°C. The I2C- and SMBUS-compatible interface features four programmable addresses.

I have attached some pics of the module and datasheet for the IC for reference.

ina3221.pdf (1.09 MB)

Front pic attached.

IMG_7909.PNG|750x1334

MarkT:
That module doesn’t bring out the 3 pairs of sense pins separately,

it cannot be used as a high-side current sensor, only low-side. Ground is used as the return for all channels.

True.

Are you sure about that.
I see one side of all shunts connected to a common via.
And the other sides of the three shunts to individual vias.
No ground connection to the shunts.

This board can only be used for high-side sensing of three loads connected to a common supply.
Not even sure if the chip is bi-directional (like the INA219).
Couldn’t find it in the datasheet, so I assume it’s not.
Leo…

Look carefully at the pictures - 3 of the 6 holes are linked to the groundplane.

MarkT: Look carefully at the pictures - 3 of the 6 holes are linked to the groundplane.

True.

But the three shunts are connected to the other three holes. And shunt common goes to a different hole on the side of the board.

It seems that this board is designed for three loads, connected to those six "power/ground" vias. And that 'power-in/ground' is on the side of the board. I wonder how much current those thin shunt traces can take before evaporating. Leo..

I thought I'd reach out to the sellers of this module to see if they could provide some useful information.....

Great customer support from chinese eBay and AliExpress stores :)

I will set up a test this afternoon with testloads on the three channels and try it high side and low side to see how that works out.

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Thanks for your email.

Sorry , I am just a customer service. I tried my best to found some info for you ,but sorry have no result.

We actually have no enough technical information can offer .

I hope to get your understanding.

Do you mind searching information online to find more technical support ?

Thank you . Best regards .

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Wawa: True.

But the three shunts are connected to the other three holes. And shunt common goes to a different hole on the side of the board.

It seems that this board is designed for three loads, connected to those six "power/ground" vias. And that 'power-in/ground' is on the side of the board. I wonder how much current those thin shunt traces can take before evaporating. Leo..

Ah, that could be. The original chip doesn't restrict you to a common supply for each shunt, so I'd expect it just to be wired in line with the high side supply separately per channel.

Or put another way the board isn't breaking out the chip connections in the way the datasheet would imply would be obvious.

I have tested the module tonight. It is definitively a high side sensor as described in the datasheet. I did a low side test just to be 100% sure. See the attached photo of the setup and the load reading. I used a computer controlled load and tried to draw 1 amp.

low side 1.PNG|963x1009

IMG_7911s.jpg|605x807

Here are the results of the high side testing. The module will, as Wawa described, let you measure three loads on the same power supply. I have attached the setups and readings from the different channels, and a setup with two loads. The negative current readings is due to the code and can easily be changed. But is was programmed to show a negative reading for current going into the battery and positive for current coming from the battery.

I have also made a small tutorial to help the next guy whose scratching his head over this module: https://youtu.be/n9tnBJ0_Rxw

IMG_7911s.jpg|605x807

IMG_7912s.jpg|605x807

IMG_7913s.jpg|605x807

IMG_7914s.jpg|605x807

IMG_7915s.jpg|605x807

IMG_7916s.jpg|605x807

high side PSU.PNG|959x1013

high side CH1.PNG|963x1004

high side CH2.PNG|966x1001

Here's the rest of the screencaps of readings.

high side 2 loads.PNG|965x1008

high side CH2.PNG|966x1001

high side CH3.PNG|971x998

Glad it works - I suppose limiting it to a single supply saves on board area, but its a shame as the chip is designed to sense upto 3 different rails for power consumption...

hello, I have found this topic after spending two days on trying to understand that, and another - INA219 module. That is very interesting for me....

I have some additional equipment in car which I would like to monitor online - 24/7 - how many power they are consume over time. I need that connected 24/7 and I can't disconnect it from main power.

I would like to build any tool which allow me to monitor the current 3 different channels. I can agree on that, the voltage value of all of them will be shared, and will have same value. But I would like to confirm - if that module - INA3221 - could usable in my case? I would like to get info like CH1 - 7A. CH2 - 1,5A, CH3 - 0,6A (only example values).

What current will be the highest possible to this board? That is not ultra-durable - one cable which supplies the whole board (POW&GND holes) I suppose?

And last, but not least - if that board will be better solution instead of 3xINA219? As I wrote - the voltage value will be constant in my case - that this is not a problem here.

So, I would be very happy for your opinion about my problem - I can change my plans with that.

Thank you for any answers have a great time !